1. Field of the Invention
The invention relates generally to apparatus and methods for connecting hoses and other fluid conduits. More particularly, the invention relates to apparatus and methods for splicing hoses and conduits in a subsea marine environment.
2. Background of the Technology
Hydraulically operated systems are deployed subsea to facilitate and support offshore drilling and production operations. The hydraulically operated system is often connected to a subsea hydraulic power source with a flexible hose that supplies hydraulic fluid pressure to operate the system. In some cases, it may be necessary to cut the hydraulic fluid supply hose to replace or repair the hydraulic power source or hydraulically operated system, and then reconnect the repaired or new power source with the hydraulic system. For example, referring now to FIGS. 1A-1C, upon failure of a subsea hydraulic power source 10, it is disconnected from a subsea hydraulically operated system 20 by cutting the hydraulic supply hose 30 extending therebetween. Cutting hose 30 results in a first hose segment 30a connected to system 20 and a second hose segment 30b connected to power source 10. Next, the non-functional power source 10 is retrieved to the surface for repair or replacement.
A repaired or new hydraulic power source 10′ is then lowered subsea and reconnected to system 20 subsea using one or more remotely operated vehicles (ROVs). As best shown in FIGS. 1B and 1C, typically, the subsea ROVs remove hose segment 30a coupled to system 20 by disconnecting a connector 31 that couples hose segment 30a to system 20. Next, a replacement hose segment 30a′ having a connector 31′ at one end and a standard ROV male connector 32 at the opposite end is connected to system 20. The repaired or new hydraulic power source 10′ is deployed with a hose segment 30b′ with a standard ROV female connector 33 that releasably connects to connector 32, thereby fluidly coupling power source 10′ to system 20.
This process enables repair or replacement of subsea hydraulic power source 10 without retrieving system 20 to the surface. However, before hose segments 30a′, 30b′ can be connected, hose segment 30a is removed and a new hose segment 30a′ is connected to system 20. Accordingly, this process is often time consuming and challenging to perform with ROVs, particularly in deepwater environments.
An alternative approach to connect two hose segments subsea (e.g., connect hose segments extending from a subsea hydraulic power source and a subsea hydraulic system) is to splice the hose segments together. Referring now to FIG. 2, a hose splicing or insertion tool 40 was developed by Oceaneering, Inc. of Houston, Tex. to connect severed hoses in an emergency situation. Tool 40 includes a conical hollow needle 41 and a cylindrical body 42 coupled to needle 41. A paddle 43 extends from body 42 and is turned by a subsea ROV to engage seals inside body 42. Paddle 43 and a pair of arms 44a, 44b extending from body 42 allow an ROV operator to stab needle 41 into a first hose segment. Body 42 includes a connector 45 that allows connection of a second hose segment to tool 40. Fluid communication between the two hose segments connected to tool 40 is provided through connector 45, body 42, and needle 41. Fluid flow through tool 40 may be monitored with a pressure gauge 46 coupled to connector 45. However, the flow area through the needle is substantially less than that of the original hose, so the connection acts as a flow restrictor, thereby reducing the effectiveness of the spliced line. In addition, it is very difficult for an ROV operator to align the needle with the end of the hose and push the needle into the hose.
Accordingly, there remains a need in the art for apparatus and methods to repair and/or install subsea devices and systems that rely on hose or other conduit connections, establish ad hoc subsea hose connections, and repair damaged or severed subsea hoses. Such apparatus and methods would be particularly well-received if they were easily manipulated, installed, and visualized by one or more subsea ROVs; easily deployed from a surface vessel; and were capable of maintaining fluid flow rates and pressures substantially the same as the original subsea hose or conduit.